I've just completed my full field test of this lens. Here's the "Executive Summary": The AF-S 80-400mm f4.5-5.6 VR is a significant and worthwhile upgrade from its predecessor. It's an incredibly versatile lens that will meet most of the needs for many, many nature and wildlife photographers.
Solid optical quality throughout the entire focal range; very "hand-holdable
Just acceptable build quality; horrendous tripod collar; poorly designed hood